Electric switch



Jan. 30, 1934. W. A. ATWOOD 1,945,389

ELECTRIC SWITCH Original Filed Nov. 4, 1951 www? Inventor'.

WinField A. Atwood, bg His Attofheg.

Patented Jan. 30, 1934 ELECTRIC SWITCH- Winfield vA. Atwood, ,Yeadoray Pa., assig-norito `Greneral- Electric. Company, a

York

corporation of New Original-applicationNovember14, 1931', Serial No; 572,924. Divided'. and this; application October. 28,1932.' SerialLNo. 640;()38

5` Claims.. (CIL 200e-89) My invention1 relates tov electric'- switches" and more particularly" to` automatic trip-free" circuit breakerswhichare intended" to` be closed usuallyv by other; thanv manualoperation and anobject'of my invention is to; provide; an` improvedrtrip-free circuit breakerV mechanism which does not require a special resetting operation before the circuit breakerv can be reclosediaiterthe-tripping thereof;

Before trip-free circuitbreakers,` with which I am" familiar, cantbe reclosedafterY tripping; a special resetting operation must' be performed after the completion ofacircuit"A breaker opening movement: Obviously, the extraoperation mV is disadvantageous, particularly; sowhere a solenoid, motor, pneumatic, orotherformv ofv operating mechanism is employed.u becauseit; necessitates additional'complications;` In accordance with my inventom IV eliminatev this extra oper- 20h ation by an improved trip-freemechanism which isv automatically reset during av part` ofv the circuit' breaker opening movement;

Thisy application isA a division ofv my application SerialNo. 572,924; led" November 4; 1931,

25 for Electric switch;

My invention will be'better understood from the following4 descriptionr when'- consideredu in connection with the accompanyingv drawingand its; scopeK will be. pointed'v out: iny theappended 3a claims:

Inthe accompanying drawing, Fig; 1- is a side elevation'V of' an-air circuitr` breaker embodying my invention, the circuit breaker being shown in the closed" positionwith certain parts, notL per- 35 tinentz to my invention, omitted: forl clearness; Fig. 2`is'a sideelevation of apart offthecircuit breaker mechanism with the circutbreakerfnearlyin'the fullopen position; vFig-l- 3 isv aside elevation with the circuitbreaker in the full 'openposition; Fig; 4 is-apartl'y sectionaldetailof a' link mechanismV for obtainingY a`A separation of the arcingcontacts disproportionate to` the movement ofV` thev movable mainv contact; and' Fig. 5 illustrates a modification of my" invention.

For the purpose of illustratingl` myl invention, I*liaveshownin lig.l 1' an solenoid operated air circuit breaker mounted on a.- switchboard'or panel 5i and* provided with: studs-fory terminals 6, statiomiry;` mainn contactsl 7; connected to the stud'az.A a movable mainY contact 8'V of" the bridging type, relatively movable cooperatingA burning-'tips or,v contacts '9* and v10,- relatively movable cooperatingffiinal1 arcing"v contacts' 11' and 12;` respectively; stationary'. and" movable; as-shown, andia blowout coil'lS whose arc chute is omitted for the sake of clarity in the illustration.

ForVv actuating the: movable contacts 8; 10' and 12 to' and fromV circuit'closing-position, theymay be, mounted onl a' movable contact` carrying o member; 14 which, as-shown', is--rotatably-mounted-on a, stationary pivot -l5inthe circuitbreaker frame 16; In ordertoactuateethe member 14 to circuit closing position, Iprovide animproved trip-free'toggle mechanismihaving at least three e5- links-17, 18V and19. The link 1T is rotatably mounted on a pivot 20 carried by the-memberrM; The link'l9 is rotatably mounted on al stationary pivoti 21v inthe frame 16. The link 18 joins-the links 1 7 and'l9 at pivots122 and*23, respectively.` 70

The linksv 17 and 1,8- form al trippingv toggle which, when rigid', forms with the third link-19 a closing toggle; Thel closing toggle may be operatedy to closev theA circuit breaker byv a solenoidmechanisrn which includes a coil* 24- mounted inthe frametl' and a movablerodor plunger 25' which; during the' circuit` closing operation', abuts a roller carried`v by the pivot 23; The-clos= ing operation may also' be performed" manually by inserting` a suitable bar in the'socket 26' ofthe linkV 19 and then'` turning this link clockwise about its pivot 2l. In order; to maintain the closingA toggle in the closed positionof the switch, as long as` the tripping toggle isrigdiI providev a holding means,y suchl as a catch 27; mounted on thev pivotV 23 and suitably; biased asr by a, spring 28to engage: av stop.. or projection 29 on the frame 1'6.

For' maintaining the tripping toggle 1171-18 rigid there may be provided, as showna latching mechanism of'th'e shock-proofv type disclosed in U'; S. Letters .Patent 1,589,924. As shown, this mechanism includesl a catch'- 30 mounted.on the pivot 20 andv arranged toengage an arm 31 on the link 18, av catch 32 mounted'on the pivot" l5 95 and varranged to engagethe catch 30", anda'spring 33 lfor biasing the catchesO'v and32. to the latch: ing or toggle restraining position. The. tripping toggl'el'l-l may be collapsed to eiiectthe openingfof'i the circuit breaker by a number oftripf- 100 pingmembers orl asingle tripping member; such as an arm 34 downwardly movable; asfshown, to engageandf release the vcatch32 andl therebyeffect the release ofthel catch 30from'theclinkf'18- Thetrippingmember'i may be manually actu- 195 ated-lor operated' in response =to abnormalicircuit conditions, or otherwise, lby any" suitable means, examples of 'whi'chare 4well knownto' the' art:

In' accordance-'withmy invention, I release Vthe closing` toggleY holding catch 2T' and reset the 110 Mmmm,

tripping toggle 17--18 so as to be ready for a reclosing operation immediately after the circuit breaker is tripped and has completed the circuit opening operation. For releasing the catch 27, I provide suitable means, such as a roller 35, which is mounted on the pivot 22 and which at a determined point in the circuit opening operation abuts the catch 27 and disengages it against the bias of the spring 28 from its stop 29. For resetting the tripping toggle during the circuit opening movement, I provide energy storing means, such as a spring 36, so mounted that during the first part of the circuit opening operation energy is stored therein, as shown in Fig. 2, and is subsequently released after the release of the catch 27 and duringthe remainder of the circuit opening operation to reset the tripping toggle 17-18, as shown in Fig. 3, where the opening movement of the circuit controlling member 14 is arrested by suitable buffer means, such as a stop 37.

Instead of using the catch 27 to maintain the holding toggle closed, I may so arrange the parts that this toggle is overset in the closed position of the circuit breaker, as shown in Fig. 5. In this case, the movement of the toggle to the overset position with the center of the pivot 23 above the line adjoining the centers of the pivots and 21 may be limited in any suitable manner as by having the arm 53 of the link 19 abut the side of the frame 16, as shown.

For the purpose of effecting a movement of the movable arcing contact 12 disproportionately greater than the movement of the main movable contact 8, I so mount the arcing contact 12 that it is movable relatively to the main contact 8 and provide means for effecting this relative movement during the circuit breaker operation. Thus,

as shown, the arcing contact 12 is mounted on a contact carrying arm 38 which is rotatably mounted on a pivot 39 carried by the circuit controlling member 14. A exible lead 40 connects the contact 12 with the lower stationary main contact 7. In order to insure the desired relative motion between the contacts 8 and 12 in the correct sequence, I provide suitable means which, as shown, includes a resiliently controlled variable length link 41 in which energy is stored during the closing operation of the circuit breaker. As shown, this link extends between the pivot 21 and a pivot 42 on the arm 38 located intermediate the pivots 15 and 39. The structure of the link 41 is such that during a part of the circuit opening operation the link gives up its stored energy to' assist in opening the circuit breaker and maintaining the arcing contacts 11 and 12 engaged. During the process of giving up its energy the link acts as a tension member, its length being decreased until after the main contacts are open the required amount when its length becomes nxed and it acts as a compression member to turn the arm 38 relatively to the member 14. Iri this way there is secured an amplified opening movement dependent on the movement of the member 14 and the movement of the arm 38 relatively thereto.

The construction of the link will be clear from Fig. 4 which shows it as including a cell or cylinder 41 within which a rod 43 is movable against the bias of a spring 45 included between a guide and retaining plunger 46 on the end of the rod within the cylinder and a bushing 47 adjustably positioned in the cylinder so that the spring compression can be varied. A lock nut 48 serves to hold the bushing 47 in any fixed position desired.

The rod 43 carries at its other end an adjustably positioned yoke 49 whereby it is possible to adjust the over-all length oi' the link so as to insure that the arcing contacts engage each other in relation to the position of the main contact 8 when and as desired. The lock nut 50 may used to insure that the yoke 49 remains in any position to which it is adjusted. For effecting the circuit opening movement of the member 14 and the movement of the arm 38 relatively thereto, suitable biasing means such as a spring 52 connected to the link 19 and to the arm 38 on the side of the pivot 39 opposite the pivot 42 may be used, the spring 52 being tensioned when the circuit breaker is closed, as shown in Fig. 1.

With the parts in the circuit closed position, shown in Fig. 1, the rod 43 is retracted from the cylinder 41 its maximum amount for any given adjustment, thus putting the spring 45 in compression so as to hold the arcing contacts 1l and 12 closed against the tension of the spring 52. If now the tripping arm 34 is actuated to engage the catch 32 whereby to release the catch 30, the tripping toggle 17-18 is collapsed to cause the opening oi' the circuit breaker. As the circuit controlling member 14 is turned clockwise about its pivot 15 under the bias due to the weightof the parts and to the springs 45 and 52, the arcing contact 12 will be maintained against the contact 1l until the desired opening is eiected between the main contacts 7 and 8. During this time in which the spring 45 is giving up its energy, relative movement between the member 14 and the arm 38 occurs, member 14 turning clockwise relatively to arm 38. When the link 41 assumes its fixed length as shown in Fig. 4, that is after the rod 43 has reached the bottom of the cylinder 41, further movement of the member 14 causes the arm 38 to turn clockwise relatively thereto since the pivot 42 is then in effect a stationary pivot. Consequently, the angular opening movement of the contact 12 is greater than the angular opening movement of the contact 8, as is clearly shown in Fig. 3.

During the opening movement the toggle reset spring 36 is stretched, as shown in Fig. 2, until the roller 35 on the pivot 22 engages and releases the catch 27 from its stop 29, as shown in Fig. 2. On further opening movement the tripping toggle 17-18 is reset by the spring 36, as shown in Fig. 3. If the circuit breaker trips While being manually operated to the closed position, the catch 27 is released, as set forth above, but the operator may hold the link 19 substantially in the position it occupies when the circuit breaker is closed as long as he pleases. Consequently, the tripping toggle does not reset until the link 19 is released so that it can move toward the position shown in Fig. 3. With the toggle reset the circuit breaker can be reclosed by energizing the solenoid 24 whose plunger 25 pushes against the roller on pivot 23 until the closing toggle assumes the position shown in Fig. 1, Where it is held by the catch 27 as it is biased into engagement with its stop 29.

During the closing movement the arm 38 is moved counter-clockwise relatively to member 14, the initial stress of spring 45 predominating over the stress being acquired by spring 52 until the arcing contact 12 engages Contact 1l, Whereupon the member 14 is moved counter-clockwise relatively to the arm 38, thus storing energy in the spring 45 and lengthening the link 41 until iro the circuit breaker is in the fully closed position, shown in 1.

While I have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangement shown but seek to cover in the appended claims all those modieations that fall Within the true spirit and scope of my invention.

What I claim as new and desire to secure by` Letters Patent of the United States, is:

1. In combination with a switch having a movable circuit controlling member, operating means therefor including a trip-free toggle mechanism having at least three links, two of said links forming a tripping toggle which, when rigid, constitutes with the third link a closing toggle, means for resetting the tripping toggle during a part of the circuit opening movement of the switch and holding means for maintaining the closing toggle rigid to hold the switch closed as long as the tripping toggle is rigid.

2. In combination with a switch having a movahle circuit controlling member, operating means therefor including a trip-free toggle mechanism having at least three links, two of said links forming a tripping toggle which, when rigid, constitutes with the third link a closing toggle, means for resetting the tripping toggle during a part of the circuit opening movement of the switch, means for holding the closing toggle rigid to hold the switch closed as long as the switching toggle is' rigid and means controlled by said tripping toggle on the collapse thereof to release the holding means of the closing toggle.

3. In combination with a switch having a movable circuit controlling member, operating means therefor including a trip-free toggle mechanism having at least three links, two of said links forming a tripping toggle which, when rigid, constitutes with the third link a closing toggle, means for resetting the tripping toggle during a part of the circuit opening movement of the switch, holding means for maintaining the closing toggle rigid to hold the switch closed as long as the tripping toggle is rigid, means controlled by said tripping toggle on the collapse thereof to release the holding means of said closing toggle and means for efecting the collapse of the tripping toggle.

4. In combination with a switch having a movable circuit controlling member, operating means therefor including a trip-free toggle mechanism having at least three links, two of said links forming a tripping toggle which, when rigid, constitutes with the third link a closing toggle, holding means for maintaining the closing toggle rigid to hold the switch closed as long as the tripping toggle is rigid, means for tripping the tripping toggle, means associated with the tripping toggle for releasing said holding means and means for resetting the tripping toggle subsequently to the release of said holding means and during a part of the circuit opening movement of the switch.

5. In combination with a switch having a movable circuit controlling member, operating means thereior including a trip-free toggle mechanism having at least three links, two of said links forming a tripping toggle which, when rigid, constitutes with the third link a closing toggle, holding p WINFIELD A. ATWOOD. 

